Anti efflorescence composition

Abstract

The present description relates to an anti-efflorescence water based composition that eliminates the efflorescence that occurs on new pavers, stones, concrete bricks or concrete furniture because of high humidity comprising a homo polymer solution of acrylic, an hydrolyzed polyvinyl alcohol and/or a combination thereof.

Claims

1. A method of preventing or removing efflorescence from pavers, concrete bricks, stones or concrete furniture comprising the step of applying a composition comprising from 0.1% to 60% by weight of a hydrolysed polyvinyl alcohol (PVOH) or a combination of a homo polymer solution of acrylic and the PVOH, at least one of phosphoric acid, nitric acid, sulfamic acid and urea/hydrochloric acid and water, on the surface of said pavers, concrete bricks, stones or concrete furniture.

2. The method of claim 1, comprising at least one acrylic polymer.

3. The method of claim 1, wherein the homo polymer has molecular weight between 1000 and 500000.

4. The method of claim 1, wherein the homo polymer has molecular weight between 1000 and 100000.

5. The method of claim 1, wherein the homo polymer has molecular weight between 4000 and 30000.

6. The method of claim 1, wherein the PVOH has a molecular weight between 10000 to 150000.

7. The method of claim 1, wherein PVOH has a molecular weight between 100000 and 130000.

8. The method of claim 1, further comprising 0.1% of at least one of phosphoric acid, nitric acid, sulfamic acid and urea/hydrochloric acid.

9. The method of claim 1, wherein the pH of said composition is neutralized up to pH 13.

10. The method of claim 9, wherein the pH of said composition has a pH between 2 and 10.

11. The method of claim 8, wherein the pH of said composition is neutralized at a pH between 4 and 6.

12. The method of claim 8, wherein the pH of the composition is neutralized by adding an alkali.

13. The method of claim 12, wherein the alkali is at least one of caustic soda, potassium hydroxide and ammonium hydroxide or other alkali.

14. The method of claim 1, wherein the composition comprises 15 to 30% of the PVOH or the combination of the homo polymer solution of acrylic and the PVOH.

15. The method of claim 1, wherein the composition comprises 20% of the PVOH or the combination of the homo polymer solution of acrylic and the PVOH.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 shows photos of an untreated (A) and treated concrete paver, wherein efflorescence is clearly seen on the untreated paver (arrows in A) versus the treated paver (B) with the composition described herein comprising sodium polyacrylate after immersing them in mineral water for 3 hours.

(2) FIG. 2 shows photos of treated concrete pavers with (A) 1.5% PVOH+1.5% sodium polyacrylate and (B) 1.5% PVOH alone wherein efflorescence was blocked.

DETAILED DESCRIPTION

(3) It is provided an anti-efflorescence water based composition that eliminates the efflorescence that occurs on new pavers, stones, concrete bricks or concrete furniture because of high humidity happening during the storage or whenever the above materials become wet for any reason.

(4) The composition described herein comprises from 1% to 60% by weight of at least one a homo polymer solution of acrylic, or hydrolysed polyvinyl alcohol or a combination thereof, and water.

(5) The composition encompassed herein can be used to prevent or remove efflorescence that has already occurred. As clearly evidenced in FIG. 1, no sign of efflorescence was seen on a treated concrete paver with the composition described herein containing an homo polymer solution of acrylic compared to an untreated paver, wherein efflorescence is clearly seen (white spots, see arrows in FIG. 1A) after immersing them in mineral water for 3 hours.

(6) The composition described herein is a water based product that reduces or eliminates efflorescence. The composition comprises a homo polymer containing from 1% to 60% by weight of a residual of at least one acrylic monomer, the molecular weight of this homo polymer being between, between 1000 to 500000, and more preferably between 4 000-100000.

(7) The composition described herein can also comprise hydrolyzed polyvinyl alcohol (PVOH). The composition can comprise for example 14% of PVOH in water at a pH of around 2.

(8) In an embodiment, the composition comprises between 5 to 60% of the polymer or PVOH. The hydrolyzed polyvinyl alcohol can be applied in combination or instead of the acrylic polymer. As seen in FIG. 2, PVOH used alone (FIG. 2B) is more effective that a combination of PVOH+sodium polyacrylate (FIG. 2A). Still, the combination of PVOH+sodium polyacrylate allowed removing and preventing efflorescence to appear almost entirely.

(9) Encompassed herein a hydrolyzed and partially hydrolyzed PVOH, with low molecular weight to high molecular weight. Molecular weight of PVOH encompassed is from 10000 to 150000, preferably between 100000 and 130000.

(10) In another embodiment, the composition can be in acid form or neutralized at pH from 2 to 11, preferably from 4-7.

(11) The concentration of the finished product is ideally adjusted to contain 14-20% of active product.

(12) The composition described herein can also comprise phosphoric acid, nitric acid, sulfamic acid or urea/hydrolic acid. The added acid will vary depending on the surface to be treated. For example in case of pavers, nitric acid is not recommended because it could react with iron content in pavers otherwise all the other acids can be used.

(13) The composition described herein can be used to remove efflorescence occurred already on the surface of pavers, stones, concrete, by covering the pavers with the composition as described herein, comprising for example 0.1% to 5% polymer in a water solution, 0.1 to 5% of polyvinyl alcohol or a combination thereof.

(14) To prevent efflorescence from occurring, the composition as described hereinabove, comprising for example 2.0% polymer or PVOH or a combination thereof is applied on the surface of the pavers or concrete to cover it completely then let to dry. This will prevent efflorescence from occurring because of the extra humidity or water.

(15) The composition of the acrylic copolymer as described herein was made for example by mixing de-ionized water; sodium metabisulfite; ammonium persulfate and glacial acrylic acid 99.5%.

(16) Alternatively, a mixture of de-ionized water; sodium metabisulfite; sodium persulfate; and glacial acrylic acid was also made.

(17) Both mixtures can be reacted at 75 to 120° C. for few hours. After the reaction and obtaining the homo polymer of acrylic acid, the product can be semi neutralized or completely neutralized by caustic soda potassium hydroxide, ammonium hydroxide or other alkalies.

(18) While the invention has been described in connection with specific embodiments thereof, it will be understood that it is capable of further modifications and this application is intended to cover any variations, uses, or adaptations of the invention following, including such departures from the present disclosure as come within known or customary practice within the art to which the invention pertains and as may be applied to the essential features hereinbefore set forth, and as follows in the scope of the appended claims.